Clues found in note among fatal plane crash wreckage
A FLIGHT instructor's hand-written note found in the wreckage of a light-aircraft was the vital clue investigators needed to understand why two men died when the plane crashed near Brisbane.
The experienced pilot and his student were flying the Diamond DA40 aircraft near Beaudesert on September 26, 2017, when it crashed nose-first into a turf farm.
Weather reports record it was near perfect flying conditions as the small plane climbed to about 4500 feet over the Archerfield training area at 9.43am.
The two men were preparing the student flyer for his upcoming Recreational Pilot Licence flight test.
But moments later the plane slowed mid-air and began spiralling to earth at a rate of about 6,000 feet per minute in a near vertical descent.
A mayday call warning the aircraft was out of control were the last words heard before the plane slammed into the ground.
"...the aircraft is in a sp...," the instructor is heard saying before the recorded transmission ended.
Local farm workers rushed to the crash site but there was little they could do to help the men. Both died at the scene.
Investigators found the handwritten note in the cockpit.
It listed a series of sequences to be conducted during the flight, including steep turns, practice forced landing and precautionary search and landing.
But it was the words 'advanced stalls' that helped the Australian Transport Safety Bureau investigation team determine the likely cause of the crash.
"The order of sequences and markings on the note aligned with the aircraft movements captured by radar," investigators said in an ATSB report released on Wednesday.
The note indicated that manoeuvres up to and including stalls had been completed.
"At the time the aircraft entered the spin, the instructor and student were likely conducting the next incomplete item on the list, which was advanced stall recovery training," the report said.
The sequence requires the student to demonstrate recovery to stable flight from the beginnings of a spin following the stall.
Investigators found the instructor and trainee pilot could not or did not recover from the spin before the plane crashed despite there being sufficient height to do so.
"It was not possible to determine whether correct recovery inputs were made during the spin without recovery, or other factors prevented recovery," investigators said.
Examination of the wreckage and aircraft maintenance history found no outstanding issues or defects.
However, the aircraft flight manual warned against intentional spinning in the plane.
Investigators also found there was no clear and consistent definition of the point at which a manoeuvre becomes a spin for the purposes of flying training.
The ATSB has now issued safety warning to pilot training schools to investigate if the planes they're using are rated for spin training.
Operators have also been told to beef up their skills and procedures so they can avoid unintentional spins and recovery.